federal-register-mcp

MCP server for the Federal Register API. Proposed rules, final rules, notices, executive orders, comment periods, and regulatory tracking since 1994.

No authentication required.

Tested and hardened through four rounds of integration testing against the live Federal Register API. 77 regression tests covering 14 P1 items including the list_agencies pydantic crash that hit every call, payload bombs, and silent-wrong-data substring matches, plus 10 P2 validation gaps fixed. See TESTING.md for the full testing record.

What it does

Exposes the Federal Register API as 8 MCP tools:

Core

• search_documents - Search with flexible filters (agency, type, term, docket, dates, RIN)
• get_document - Full details for a single document by number
• get_documents_batch - Fetch up to 20 documents in one call
• get_facet_counts - Document counts by type, agency, or topic
• get_public_inspection - Pre-publication documents with client-side filtering
• list_agencies - All ~470 agencies with slugs

Workflow

• open_comment_periods - Currently open comment periods (sorted by deadline)
• far_case_history - Full rulemaking history for a FAR/DFARS case

No authentication required

The Federal Register API is fully public. No key, no registration.

Installation

uvx federal-register-mcp

Claude Desktop configuration

{
  "mcpServers": {
    "federal-register": {
      "command": "uvx",
      "args": ["federal-register-mcp"]
    }
  }
}

Example prompts

• "What FAR cases have open comment periods right now?"
• "Show me the full rulemaking history for FAR Case 2023-008."
• "Find all proposed rules from DoD published in the last 6 months."
• "What significant rules has GSA published this fiscal year?"
• "Are there any pre-publication documents related to procurement today?"
• "How many proposed rules vs final rules has the SBA published since January?"
• "Find executive orders related to federal acquisition from the last year."

Companion tools

• ecfr-mcp: what the regulation currently says (the book)
• federal-register-mcp: what is changing (the newspaper)

Together they cover the full regulatory pipeline. Use far_case_history to trace a rulemaking from proposal through final rule, then ecfr-mcp to read the codified result.

License

MIT